【作者】 齐冬冬；

【导师】 姜建壮；

【作者基本信息】 山东大学 ， 无机化学， 2010， 硕士

【摘要】 卟啉是一类广泛存在于自然界中的化合物。它具有特殊生物活性。卟啉类化合物的最基本的结构是卟吩,即四个吡咯单元的氮原子朝向中心并通过四个碳桥连在一起的封闭连续共轭体系。卟吩有十二个可取代位置。这些位置被不同取代基取代后的衍生物称为卟啉。把卟吩的四个中位碳用氮原子取代而得到的化合物被称为四氮杂卟啉,再在稠合四个苯环之后产生的化合物叫做酞菁,亦被称作四氮杂四苯并卟啉。由于四个苯环参加了共轭,所以酞菁的共轭体系比卟啉大。萘菁可以看作一类取代酞菁,是在酞菁的苯环上再稠合四个苯环,这样萘菁环上共有二十四个位置可以被取代,共轭体系比酞菁更大。以上化合物均为平面结构。如果减少一个吡咯单元,则可变为亚卟啉、三氮杂亚卟啉、亚酞菁和亚萘菁。这种结构则成为锥形共轭结构。其共轭性有所降低,且共轭体系有所减小1.酞菁类似物的大环内质子转移研究由于卟啉和酞菁、以及四氮杂卟啉的优异性质,近年来对它们的化学、生物学和材料学研究比较多.它们的传统应用领域是染料与颜料。近年来,这种四吡咯化合物的应用领域扩展到了激光打印机的感光材料、光能存储材料等领域。由于它们的高度稳定性和广泛的配位能力,它们又被认为拥有染料敏化太阳能电池、化学反应的催化剂、气体探针、非线性光限制材料、光动力学治疗和抗腐蚀剂的潜力。卟啉在生命过程中扮演者重要角色,如光合作用中叶绿素的作用、氧气的运输与活化中细胞色素和血红素的作用。在由四个N组建的空穴中,质子的转移在卟啉生命过程中起着至关重要的作用,这种转移被称为N-H互变异构。二十世纪末和二十一世纪初,N-H互变异构在实验上和理论上都进行了研究。现在普遍认为,N-H互变异构是通过分步反应实现的,反应时快速经过邻位中间体。在当今的科研界,卟啉酞菁虽然是热点分子,但是它们的等电子体四氮杂卟啉却没有得到应有的重视。2004年,Huang和Ma等人用DFT方法研究了四氮杂卟啉的环内N-H互变异构现象,发现质子可以在室温下很容易的在四个N组建的空穴中跳转。而且,前人的研究中还发现,当有苯环在卟啉／四氮杂卟啉的外围稠合的时候,π共轭体系将会增大,造成该体系的光谱性质发生重大改变。然而,这种π共轭体系的增大方式,对空穴内的质子转移是否有影响,这一点尚不明确。这样研究也有利于加深我们对生物过程的理解、设计更好的生物替代品。我们的研究工作集中在不对称四氮杂卟啉和酞菁的大环内N-H互变异构的DFT研究上,研究的体系是从四氮杂卟啉H2TAP (A0B0C0D0),通过中间物质酞菁H2Pc (A1B1C1D1)直到萘菁H2Nc (A2B2C2D2)。我们还研究了这三种物质之间的各种不对称化合物。在B3LYP/6-31G (d)水平上,我们对这11种化合物(从A0B0C0D0到A2B2C2D2)的全部可能的反应路径均进行了优化和频率计算,以期找到合适的反应路径。另外,为了确认规律的普适性,我们又对严重不对称的几种化合物(A0B0CmDn, m≤n≤3)进行了同水平的计算。最后,我们系统讨论了环内氢转移的势垒和邻位中间体的稳定性。2.亚酞菁类似物的分子轨道与谱学研究三氮杂亚卟啉(SubTAP)和亚酞菁(SubPc)是一种锥形的大环共轭体系,由三个吡咯或异吲哚单元相互桥联而形成。三氮杂亚卟啉和亚酞菁分别是四氮杂卟啉(TAP)和酞菁(Pc)的类似物,但是subTAP和subPc的π共轭体系比TAP和Pc的π共轭体系更小。由于四氮杂卟啉和酞菁的特殊的TAP和Pc的π共轭体系已经被进行了很深刻的研究,但是subTAP和subPc并没有被深刻的关注。近几年,亚酞菁在以下几个领域得到了一定程度的研究：非线性光学材料,有机发光二极管,光伏材料,生物分子靶标,多组分D-A体系。这些性质与它们的特殊的分子结构、谱学性质和电子结构有关。另外,亚酞菁是一种合成不对称酞菁衍生物的一种很好的初始反应物。密度泛函理论(DFT)和含时密度泛函理论(TDDFT)被证明为在卟啉、四氮杂卟啉、酞菁和萘菁的能量最低构型、电子布居、分子轨道、红外光谱、电子转移和电子吸收谱这几个方面的计算上是合适的。最近,Kobayashi等人在半经验Pariser-Parr-Pople理论基础上,研究了三氮杂亚卟啉、亚酞菁、亚萘菁这三种对称性分子的分子轨道。几年后,对亚酞菁这个分子的对比性理论研究渐渐展开,分别在HF/STO-3G, HF/3-21G, HF/6-31G, B3LYP/STO-3G, B3LYP/3-21G, B3LYP/6-31G, and B3LYP/6-31G(d)这七种计算水平上,对亚酞菁进行了研究。这些研究表明,B3LYP/6-31G(d)对亚酞菁的计算是合适的。同时,亚酞菁的前线轨道也在B3LYP/6-31G(d)进行了讨论。亚酞菁的非线性光学性质在B3LYP/6-31G(d)基础上和ZINDO/S-CIS基础上进行了讨论。其芳香性和亲电性在B3LYP/6-31 G+(d)//B3LYP/6-31 G(d)水平上也进行了研讨。而且,三氮杂亚卟啉的分子轨道也在B3LYP/6-31G(d)和B3LYP/6-31G(d,p)水平上进行了计算,证明这两种方法计算结果基本没有差别。然而,在三氮杂亚卟啉、亚酞菁、亚萘菁的衍生物上,尚无系统的电子布居、分子轨道、红外光谱、电子转移和电子吸收谱的研究,尤其是不对称的亚酞菁衍生物。在本章中,我们利用DFT和TDDFT描述了亚三氮杂卟啉、亚酞菁和亚萘菁,尤其是他们之间的不对称过渡结构AaBbCc(3(?)a,b,c(?)0).同时,我们重点研究了外围稠合苯环对亚三氮杂卟啉和亚酞菁、亚萘菁衍生物的结构和性质的影响。更多还原

【Abstract】 1. Inner Hydrogen Atom Transfer in Benzo-Fused Low Symmetrical Metal Free Tetraazaporphyrin and Phthalocyanine Analogues:Density Functional Theory StudiesDensity functional theory (DFT) calculations were carried out to study the inner hydrogen atom transfer in low symmetrical metal free tetrapyrrole analogues ranging from tetraazaporphyrin H2TAP (A0B0C0D0) to naphthalocyanine H2Nc (A2B2C2D2) via phthalocyanine H2Pc (A1B1C1D1). All the transition paths of sixteen different compounds (A0B0C0D0-A2B2C2D2 and A0B0CmDn, m≤n≤3) are fully optimized at the B3LYP/6-31G(d) level and vibration analyses have been conducted to verify the optimized structures. It is revealed that the number and position of fused benzene rings onto the TAP skeleton have significant effect on the potential energy barrier of the inner hydrogen atom transfer. Introducing fused benzene rings onto the hydrogen-releasing pyrrole rings can increase the transitivity of inner hydrogen atom and thus lower the transfer barrier of this inner hydrogen atom while fusing benzene rings onto the hydrogen-accepting pyrrole rings will increase the hydrogen transfer barrier to this pyrrole ring. The transient cis-isomer interintermediate with hydrogen atoms joined to the two adjacent pyrrole rings with less fused benzene rings is much stable than the others. It is also found that the benzene rings fused directly onto pyrrole rings have more effect on the inner hydrogen atom transfer than the outer benzene rings fused onto the periphery of isoindole rings. The present work, representing the first effort towards systematically understanding the effect of ring enlargement through asymmetrical peripheral fusion of benzene ring(s) onto the TAP skeleton on the inner hydrogen transfer of tetrapyrrole derivatives, will be helpful in clarifying the N-H tautomerization phenomenon and detecting the cis-porphyrin isomer in bio-systems.2. Design, Synthesis, Characterization, and OFET Properties of Amphiphilic Heteroleptic Tris(phthalocyaninato) Europium(Ⅲ) Complexes. The Effect of Crown Ether Hydrophilic SubstituentsSubtriazaporphyrin (SubTAP) and subphthalocyanine (SubPc) are cone-shaped macrocyclic compounds consisting of three pyrrole or isoindole units around a boron atom. As the analogues of tetreazaporphyrin (TAP) and phthalocyanine (Pc) with smallerπ-peripheral conjugated system, SubTAP and SubPc have received considerable attention in recent years due to their potential applications as chromophores in nonlinear optical materials, organic lighting emitting displays (OLEDs), photovoltaic devices, tagged molecule for biochemical system, and multicomponent donor-acceptor systems associated with their distinct structural, optical, and electronic properties. In addition, subphthalocyanines have been employed as good starting material for synthesizing asymmetric substituted phthalocyanine compounds.Density functional theory (DFT) and time dependent density functional theory (TDDFT) methods have proved suitable for calculating the energy-minimized structure, electronic distribution, molecular orbitals, infrared (IR) spectrum, electronic transfer, and electronic absorption spectra of a series of porphyrin and phthalocyanine derivatives. This seems also true for the subtriazaporphyrin and subphthalocyanine analogues. Recently, Kobayashi and co-workers investigated the molecular orbitals of symmetrical subtriazaporphyrin (SubTAP, A0B0C0), subphthalocyanine (SubPc, A1B1C1), and subnaphthalocyanine (SubNc, A2B2C2) with the semi-empirical Pariser-Parr-Pople method1. A few years later, comparative calculations on the structure of subphthalocyanine (SubPc, A1B1C1) with different levels including HF/STO-3G, HF/3-21G, HF/6-31G, B3LYP/STO-3G, B3LYP/3-21G, B3LYP/6-31G, and B3LYP/6-31G(d) revealed that B3LYP/6-31G(d) was the most suitable method for calculation of subphthalocyanine systems. The frontier molecular orbitals of subphthalocyanine (SubPc, A1B1C1) were also discussed at the level of B3LYP/6-31G(d). The nonliner optical properties of subphthalocyanine (SubPc, A1B1C1) were calculated at the B3LYP/6-31G(d) level using the ZINDO/S-CIS method. The aromaticity and electrophilicity index of subphthalocyanine (SubPc, A1B1C1) were calculated at the B3LYP/6-31G+(d)//B3LYP/6-31G(d) level. Moreover, the frontier orbitals of subtriazaporphyrin (SubTAP, A0B0C0) were also calculated at the B3LYP/6-31G(d) and B3LYP/6-31G(d,p) levels, revealing the similar results for the molecular orbital calculations. However, it appears that there still exists no theoretical work at the DFT level to systematically study the structure, electronic distribution, molecular orbitals, infrared (IR) spectra, and electronic absorption spectra of a full series of SubTAP and SubPc derivatives especially their benzo-fused low symmetrical analogues.In this paper, we describe the structures and properties of fluoroboron-subtriazaporphyrin (SubTAP) and their benzo-fused low symmetric analogues AaBbCc(3≥a,b,c≥0) investigated on the basis of density functional theory (DFT) and time-dependant density functional theory (TDDFT) calculations. The effect of fused-benzene ring(s) on the structures and properties was also revealed.更多还原